While the water vapor content of the combustion gas in natural gas-fired land-based turbines is ∼10%, it can be 20–85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1-h and 100-h cycles) were performed in air with 10, 50, and 90 vol. % water vapor and CO2-10% H2O and compared to prior results in dry air or O2. Two types of TBCs were investigated: (1) diffusion bond coatings (Pt-diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high-velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air plasma-sprayed YSZ top coatings on superalloys X4, 1483, or 247 substrates. For both types of coatings exposed in 1-h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt-diffusion coatings which were unaffected by the environment. In 100-h cycles, environment was less critical, perhaps because coating failure was chemical (i.e., due to interdiffusion) rather than mechanical. In both 1-h and 100-h cycles, CO2 did not appear to have any negative effect on coating lifetime.
The Effect of Environment on Thermal Barrier Coating Lifetime
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6156
e-mail: pintba@ornl.gov
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6064
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6063
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6156
e-mail: pintba@ornl.gov
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6064
Oak Ridge National Laboratory,
Oak Ridge, TN 37831-6063
Contributed by the Manufacturing Materials and Metallurgy Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received November 12, 2015; final manuscript received December 23, 2015; published online March 15, 2016. Editor: David Wisler.
The United States Government retains, and by accepting the article for publication, the publisher acknowledges that the United States Government retains, a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Pint, B. A., Unocic, K. A., and Allen Haynes, J. (March 15, 2016). "The Effect of Environment on Thermal Barrier Coating Lifetime." ASME. J. Eng. Gas Turbines Power. August 2016; 138(8): 082102. https://doi.org/10.1115/1.4032438
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